UnitedPlugins have discounted Transmutator, a tool that crossfades between two inputs in a multitude of ways. The regular price is €69, but you may get it for €35 until April 11. A 15-days fully working trial version is available.
UnitedPlugins describes Transmutator:
Place the plugin on your track and feed a second track into its sidechain input. Then use the Mix dial to transition from A to B using 16 unique modes.
Transmutator has many uses including transitioning between different sections in tracks (from verse to chorus or build-up to drop, for example), mixing between two songs (such as in a DJ set), or sound design (by fusing and morphing two elements together in various ways).